Question

The equation of a line AB is 4x - 4y + 9 = 0, the angle made by this line with x -axis is _________.

• A. ${45}^{\circ }$
• B. ${30}^{\circ }$
• C. ${60}^{\circ }$
• D. ${75}^{\circ }$

Answer 1

The correct option is A

${45}^{\circ }$

The given line is 4x - 4y + 9 = 0 which can be written as

4x + 9 = 4y

y = x + $\frac{9}{4}$

Comparing it with the slope intercept form of line y = mx + c where 'm' is the slope of the line, we get m = 1

$\therefore m=tan\theta =1$

Hence, $\theta$ = ${45}^{\circ }$